Numerous examples of devices of this type are known.
Documents US-A1-2004//01164260 and US-B2-6.757.919 describe and represent such devices.
They are devices in which a rotary cam directly actuates the second end of the actuating finger that is intended to act on the rod of the shutter. The actuating finger is returned by a return spring.
This design has the disadvantage of constantly subjecting the finger, and consequently the cam, to the return force exerted by the spring. As a result, such a device has to provide a motor to drive the cam which is relatively powerful and consequently not very energy-efficient.
In particular, when it is intended for self-contained use, such a design requires the employment of motor supply batteries that are costly and bulky.
Also known in the prior art are designs according to which the actuating finger is directly acted upon by an electromagnet and is itself returned by a return spring. To keep the flushing system open for sufficiently long to achieve a satisfactory flow, the electromagnet must be acted upon continuously and it is therefore for this reason also not very energy-efficient.